1wcstoul(3C) Standard C Library Functions wcstoul(3C)
2
6 wcstoul, wcstoull - convert wide-character string to unsigned long
7
9 #include <wchar.h>
10 unsigned long wcstoul(const wchar_t *restrict nptr,
12 wchar_t **restrict endptr, int base);
13 unsigned long long wcstoull(const wchar_t *restrict nptr,
16 wchar_t **restrict endptr, int base);
17
20 The wcstoul() and wcstoull() functions convert the initial portion of
21 the wide-character string pointed to by nptr to unsigned long and
22 unsigned long long representation, respectively. First they decompose
23 the input wide-character string into three parts:
24 1. An initial, possibly empty, sequence of white-space wide-
26 character codes (as specified by the function iswspace(3C))
27 2.
29 Asubject sequence interpreted as an integer represented in
30 some radix determined by the value of base
31 3. a final wide-character string of one or more unrecognized
33 wide-character codes, including the terminating null wide-
34 character code of the input wide character string
35 They then attempt to convert the subject sequence to an unsigned inte‐
38 ger and return the result.
39 If the value of base is 0, the expected form of the subject sequence is
42 that of a decimal constant, an octal constant, or a hexadecimal con‐
43 stant, any of which may be preceded by a `+' or a `−' sign. A decimal
44 constant begins with a non-zero digit, and consists of a sequence of
45 decimal digits. An octal constant consists of the prefix `0', option‐
46 ally followed by a sequence of the digits `0' to `7' only. A hexadeci‐
47 mal constant consists of the prefix `0x' or `0X', followed by a
48 sequence of the decimal digits and letters `a' (or `A') to `f' (or
49 `F'), with values 10 to 15, respectively.
50 If the value of base is between 2 and 36, the expected form of the sub‐
53 ject sequence is a sequence of letters and digits representing an inte‐
54 ger with the radix specified by base, optionally preceded by a `+' or
55 a `−' sign, but not including an integer suffix. The letters from `a'
56 (or `A') to `z' (or `Z') inclusive are ascribed the values 10 to 35;
57 only letters whose ascribed values are less than that of base are per‐
58 mitted. If the value of base is 16, the wide-character codes `0x' or
59 `0X' may optionally precede the sequence of letters and digits, follow‐
60 ing the sign, if present.
61 The subject sequence is defined as the longest initial subsequence of
64 the input wide-character string, starting with the first wide-character
65 code that is not a white space and is of the expected form. The subject
66 sequence contains no wide-character codes if the input wide-character
67 string is empty or consists entirely of white-space wide-character
68 codes, or if the first wide-character code that is not a white space
69 is other than a sign or a permissible letter or digit.
70 If the subject sequence has the expected form and the value of base is
73 0, the sequence of wide-character codes starting with the first digit
74 is interpreted as an integer constant. If the subject sequence has the
75 expected form and the value of base is between 2 and 36, it is used as
76 the base for conversion, ascribing to each letter its value as given
77 above. If the subject sequence begins with a minus sign, the value
78 resulting from the conversion is negated. A pointer to the final wide
79 character string is stored in the object pointed to by endptr, pro‐
80 vided that endptr is not a null pointer.
81 If the subject sequence is empty or does not have the expected form, no
84 conversion is performed; the value of nptr is stored in the object
85 pointed to by endptr, provided that endptr is not a null pointer.
86 The wcstoul() function does not change the setting of errno if success‐
89 ful.
90 Since 0, {ULONG_MAX}, and {ULLONG_MAX} are returned on error and 0 is
93 also a valid return on success, an application wanting to check for
94 error situations should set errno to 0, then call wcstoul() or
95 wcstoull(), then check errno.
96 The wcstoul() and wcstoull() functions do not change the setting of
99 errno if successful.
100
102 Upon successful completion, wcstoul() and wcstoull() return the con‐
103 verted value, if any. If no conversion could be performed, 0 is
104 returned and errno may be set to indicate the error. If the correct
105 value is outside the range of representable values, {ULONG_MAX} or
106 {ULLONG_MAX}, respectively, is returned and errno is set to ERANGE.
107
109 The wcstoul() and wcstoull() functions will fail if:
110 EINVAL The value of base is not supported.
112 ERANGE The value to be returned is not representable.
115 The wcstoul() and wcstoull() functions may fail if:
119 EINVAL No conversion could be performed.
121
124 Unlike wcstod(3C) and wcstol(3C), wcstoul() and wcstoull() must always
125 return a non-negative number; using the return value of wcstoul() for
126 out-of-range numbers with wcstoul() or wcstoull() could cause more
127 severe problems than just loss of precision if those numbers can ever
128 be negative.
129
131 See attributes(5) for descriptions of the following attributes:
132 ┌─────────────────────────────┬─────────────────────────────┐
137 │ATTRIBUTE TYPE │ATTRIBUTE VALUE │
138 ├─────────────────────────────┼─────────────────────────────┤
139 │Interface Stability │Standard │
140 ├─────────────────────────────┼─────────────────────────────┤
141 │MT-Level │MT-Safe │
142 └─────────────────────────────┴─────────────────────────────┘
143
145 isspace(3C), iswalpha(3C), scanf(3C), wcstod(3C), wcstol(3C),
146 attributes(5), standards(5)
147SunOS 5.11 1 Nov 2003 wcstoul(3C)